Gravity Probe-B

[waterford]

Slide 79, Lecture 1 references Stanford's current experiment to verify some General Relativity issues. Current status can be found here:
http://einstein.stanford.edu/highlights/hl.html
Monthly updates are provided with the next one on 28 Feb. Evaluation of data is still in progress. No preliminary results are provided.
BTW, Robert, thanks for providing the new website location.

[baudrunner]

The project's purpose:

..is to test two extraordinary, unverified predictions of Albert Einstein's general theory of relativity. They will measure how space and time are warped by the presence of the Earth, and, more profoundly, how the Earth's rotation drags space-time around with it

It has been shown that dense concentrations of material in the inconsistant make-up of a body's overall composition can affect gravity. Such concentrations exist on the earth as well as on the moon. No doubt much difficulty in dealing with data from the GP-B probe will result from such anomalies.

The U.S. Geological Survey has studied gravity anomalies as outlined in this article.

Gravity is not the same everywhere on Earth, but changes with many known and measurable factors, such as tidal forces. Gravity surveys exploit the very small changes in gravity from place to place that are caused by changes in subsurface rock density.

[waterford]

The Feb. 28 report states that results will be presented at the April 2007 APS symposium.